login
A260063
Number of (n+2) X (1+2) 0..1 arrays with each 3 X 3 subblock having clockwise perimeter pattern 00000001 00000011 or 00000111.
1
48, 91, 256, 557, 956, 2131, 5088, 10235, 20242, 45355, 99168, 201609, 422888, 924655, 1959672, 4072719, 8679398, 18623703, 39243888, 82677405, 176286268, 374837907, 791289656, 1676354907, 3565263074, 7557825083, 15992930920
OFFSET
1,1
LINKS
FORMULA
Empirical: a(n) = a(n-1) + 4*a(n-3) + 5*a(n-4) - 5*a(n-5) - 2*a(n-6).
Empirical g.f.: x*(48 + 43*x + 165*x^2 + 109*x^3 - 205*x^4 - 64*x^5) / (1 - x - 4*x^3 - 5*x^4 + 5*x^5 + 2*x^6). - Colin Barker, Dec 28 2018
EXAMPLE
Some solutions for n=4:
..1..1..0....0..0..1....0..1..1....1..1..1....0..0..1....0..1..1....0..0..0
..1..0..0....0..1..1....0..0..0....0..0..0....0..1..1....0..0..0....0..0..0
..0..0..0....0..0..0....0..0..0....0..0..0....0..0..0....0..0..0....0..1..1
..0..0..0....0..0..0....0..1..0....1..0..0....0..0..0....0..0..1....0..0..1
..0..0..1....0..1..1....0..1..0....0..0..0....0..0..1....0..1..1....0..0..0
..0..1..1....0..1..1....0..0..0....0..0..0....0..0..0....0..0..0....0..0..0
CROSSREFS
Column 1 of A260070.
Sequence in context: A260980 A260070 A260973 * A211723 A274899 A218486
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jul 14 2015
STATUS
approved